Field of the Invention
This invention pertains to electronic watch and clock timing analyzer equipment.
There are two methods generally used in the prior art for regulating clocks and watches with electronic timing analyzers. The first such method involves comparison of the frequency of beats (ticks) from a watch or clock to a fixed frequency. The second such method involves measurement of the time interval between beats (hereinafter referred to as "beat interval"), generally using a timer running at a much higher frequency than the timepiece's beat frequency.
Prior art commercial timing analyzers have used fixed frequency generators, which produce frequencies corresponding to common beat frequencies of clocks and watches. Some of the commonest values are 3,600; 18,000; 19,200; 19,800; 21,600; and 28,800 beats per hour. These timing analyzers allow the repair person to select one of the available frequencies, and then compare the beat frequency of the timepiece to it. A simple example is the drum used in the WatchMaster Watch-Rate Recorder; this drum spins at a strictly regulated rate of 5 revolutions per second, and every time a beat occurs a mark is recorded on the paper wrapped around the drum, (and the pen which marks the paper is moved slightly, in a direction parallel to the axis of the drum). If the watch is beating at exactly 5 beats per second, then a straight line will be marked across the paper. Any variations in rate will show up in deviations from that line. This approach has a distinct advantage in that beat frequency errors are very easily read and interpreted by the repair person.
The second technique used, that of measuring the time interval between beats (the reciprocal of the beat frequency), has the significant advantage of allowing much wider variation in the beat frequencies that can be measured easily. Currently available prior art devices which use this approach generally are of two kinds. The first kind displays on a digital display a numerical average of beat interval measurements (the user controls how many interval measurements are averaged together). This sort has the advantage of being simple to operate, but has the drawback of being difficult to read and interpret, especially if the beat rate is high. The second kind of prior art device displays, on a digital display, graphs of each beat interval, presented so as to resemble the results of the "drum method" mentioned above. This has the advantage of being easy to read and interpret, but has the drawback that it does not display the numerical average of a number of beat interval measurements; consequently, if presented with an antique watch or clock which does not run at one of the common beat frequencies, the user cannot determine what average frequency it is running at in order to get an idea of the ideal beat frequency for the timepiece.